Surgical shaft assemblies with flexible interfaces

ABSTRACT

A slip ring assembly is used with a surgical shaft assembly. The slip ring assembly includes a slip ring, a first conductor mounted on the slip ring, a commutator rotatable relative to the slip ring, and a second conductor mounted on the commutator. The slip ring assembly further includes a flexible member disposed between the slip ring and the commutator. The flexible member comprises a body and flexible protrusions extending from the body, wherein the flexible protrusions are elastically deformed against the first slip ring.

TECHNICAL FIELD

The present disclosure relates to surgical instruments and, in various circumstances, to surgical stapling and cutting instruments and staple cartridges therefor that are designed to staple and cut tissue.

BACKGROUND

In a motorized surgical stapling and cutting instrument it may be useful to measure the position and velocity of a cutting member in an initial predetermined time or displacement to control speed. Measurement of position or velocity over an initial predetermined time or displacement may be useful to evaluate tissue thickness and to adjust the speed of the remaining stroke based on this comparison against a threshold.

While several devices have been made and used, it is believed that no one prior to the inventors has made or used the device described in the appended claims.

SUMMARY

In one aspect, a slip ring assembly is used with a surgical shaft assembly. The slip ring assembly includes a first connector, a first conductor mounted on the first connector, a second connector rotatable relative to the first connector, and a second conductor mounted on the second connector, wherein the second conductor is in contact with the first conductor. An interface is positioned between the first connector and the second connector, wherein the interface is configured to trap water away from at least one of the first conductor and the second conductor.

A surgical shaft assembly includes a proximal shaft portion that includes a proximal connector supported in the proximal shaft portion and first conductors mounted on the proximal connector. The shaft assembly also includes a distal shaft portion rotatable relative to the proximal shaft portion. The distal shaft portion includes a distal connector supported in the distal shaft portion, second conductors mounted on the distal connector, wherein the second conductors are spaced apart laterally and radially from one another, and a gasket disposed between the proximal connector and the distal connector, wherein the gasket is configured to resist water flow toward at least one of the first conductors and the second conductors.

In one aspect, a slip ring assembly is used with a surgical shaft assembly. The slip ring assembly includes a slip ring, a first conductor mounted on the slip ring, a commutator rotatable relative to the slip ring, and a second conductor mounted on the commutator. The slip ring assembly also includes a flexible member disposed between the slip ring and the commutator, wherein the flexible member includes a body and flexible protrusions extending from the body, wherein the flexible protrusions are elastically deformed against the first slip ring.

FIGURES

The novel features of the various aspects described herein are set forth with particularity in the appended claims. The various aspects, however, both as to organization and methods of operation may be better understood by reference to the following description, taken in conjunction with the accompanying drawings as follows:

FIG. 1 is a perspective view of a surgical instrument that has a shaft assembly and an end effector in accordance with one or more aspects of the present disclosure.

FIG. 2 is an exploded assembly view of a portion of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

FIG. 3 is an exploded view of an end effector of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

FIG. 4 is perspective view of an RF cartridge and an elongate channel adapted for use with the RF cartridge according to one aspect of the present disclosure.

FIG. 5 is an exploded assembly view of portions of the interchangeable shaft assembly of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

FIG. 6 is another exploded assembly view of portions of the interchangeable shaft assembly of FIG. 1 according to one aspect of this disclosure.

FIG. 7 is a cross-sectional view of a portion of the interchangeable shaft assembly of FIG. 1 according to one aspect of this disclosure.

FIG. 8 is a perspective view of a portion of the shaft assembly of FIG. 1 with the switch drum omitted for clarity.

FIG. 9 is another perspective view of the portion of the interchangeable shaft assembly of FIG. 1 with the switch drum mounted thereon.

FIG. 10 is a planar view of a slip ring of a slip ring assembly according to one aspect of the present disclosure.

FIG. 11 is a planar view of a distal connector of a slip ring assembly according to one aspect of the present disclosure.

FIG. 12 is a planar view of a flexible member assembled with a distal connector according to one aspect of the present disclosure.

FIG. 13 is a planar view of a flexible member assembled with a distal connector according to one aspect of the present disclosure.

FIG. 14 is a cross-sectional view of a slip ring assembly according to one aspect of the present disclosure.

DESCRIPTION

Applicant of the present application owns the following U.S. Patent Applications that were filed on Jun. 28, 2017 and which are each herein incorporated by reference in their respective entireties:

-   -   U.S. patent application Ser. No. 15/635,628, entitled         ARTICULATION STATE DETECTION MECHANISMS, now U.S. Patent         Application Publication No. 2019/0000555;     -   U.S. patent application Ser. No. 15/635,677, entitled SURGICAL         SHAFT ASSEMBLIES WITH INCREASED CONTACT PRESSURE, now U.S.         Patent Application Publication No. 2019/0000528;     -   U.S. patent application Ser. No. 15/635,707, entitled SURGICAL         SHAFT ASSEMBLIES WITH SLIP RING ASSEMBLIES FORMING CAPACITIVE         CHANNELS, now U.S. Patent Application Publication No.         2019/0000530;     -   U.S. patent application Ser. No. 15/635,734, entitled METHOD OF         COATING SLIP RINGS, now U.S. Patent Application Publication No.         2019/0000468; and     -   U.S. patent application Ser. No. 15/635,768, entitled SURGICAL         SHAFT ASSEMBLIES WITH WATERTIGHT HOUSINGS, now U.S. Pat. No.         10,211,586.

Certain aspects are shown and described to provide an understanding of the structure, function, manufacture, and use of the disclosed devices and methods. Features shown or described in one example may be combined with features of other examples and modifications and variations are within the scope of this disclosure.

The terms “proximal” and “distal” are relative to a clinician manipulating the handle of the surgical instrument where “proximal” refers to the portion closer to the clinician and “distal” refers to the portion located further from the clinician. For expediency, spatial terms “vertical,” “horizontal,” “up,” and “down” used with respect to the drawings are not intended to be limiting and/or absolute, because surgical instruments can used in many orientations and positions.

The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a surgical system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, an element of a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features.

Example devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. Such devices and methods, however, can be used in other surgical procedures and applications including open surgical procedures, for example. The surgical instruments can be inserted into a through a natural orifice or through an incision or puncture hole formed in tissue. The working portions or end effector portions of the instruments can be inserted directly into the body or through an access device that has a working channel through which the end effector and elongated shaft of the surgical instrument can be advanced.

FIGS. 1-9 depict a motor-driven surgical instrument 10 for cutting and fastening that may or may not be reused. In the illustrated examples, the surgical instrument 10 includes a housing 12 that comprises a handle assembly 14 that is configured to be grasped, manipulated, and actuated by the clinician. The housing 12 is configured for operable attachment to an interchangeable shaft assembly 200 that has an end effector 300 operably coupled thereto that is configured to perform one or more surgical tasks or procedures. In accordance with the present disclosure, various forms of interchangeable shaft assemblies may be effectively employed in connection with robotically controlled surgical systems. The term “housing” may encompass a housing or similar portion of a robotic system that houses or otherwise operably supports at least one drive system configured to generate and apply at least one control motion that could be used to actuate interchangeable shaft assemblies. The term “frame” may refer to a portion of a handheld surgical instrument. The term “frame” also may represent a portion of a robotically controlled surgical instrument and/or a portion of the robotic system that may be used to operably control a surgical instrument. Interchangeable shaft assemblies may be employed with various robotic systems, instruments, components, and methods disclosed in U.S. Pat. No. 9,072,535, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, which is herein incorporated by reference in its entirety.

FIG. 1 is a perspective view of a surgical instrument 10 that has an interchangeable shaft assembly 200 operably coupled thereto according to one aspect of this disclosure. The housing 12 includes an end effector 300 that comprises a surgical cutting and fastening device configured to operably support a surgical staple cartridge 304 therein. The housing 12 may be configured for use in connection with interchangeable shaft assemblies that include end effectors that are adapted to support different sizes and types of staple cartridges, have different shaft lengths, sizes, and types. The housing 12 may be employed with a variety of interchangeable shaft assemblies, including assemblies configured to apply other motions and forms of energy such as, radio frequency (RF) energy, ultrasonic energy, and/or motion to end effector arrangements adapted for use in connection with various surgical applications and procedures. The end effectors, shaft assemblies, handles, surgical instruments, and/or surgical instrument systems can utilize any suitable fastener, or fasteners, to fasten tissue. For instance, a fastener cartridge comprising a plurality of fasteners removably stored therein can be removably inserted into and/or attached to the end effector of a shaft assembly.

The handle assembly 14 may comprise a pair of interconnectable handle housing segments 16, 18 interconnected by screws, snap features, adhesive, etc. The handle housing segments 16, 18 cooperate to form a pistol grip portion 19 that can be gripped and manipulated by the clinician. The handle assembly 14 operably supports a plurality of drive systems configured to generate and apply control motions to corresponding portions of the interchangeable shaft assembly that is operably attached thereto.

FIG. 2 is an exploded assembly view of a portion of the surgical instrument 10 of FIG. 1 according to one aspect of this disclosure. The handle assembly 14 may include a frame 20 that operably supports a plurality of drive systems. The frame 20 can operably support a “first” or closure drive system 30, which can apply closing and opening motions to the interchangeable shaft assembly 200. The closure drive system 30 may include an actuator such as a closure trigger 32 pivotally supported by the frame 20. The closure trigger 32 is pivotally coupled to the handle assembly 14 by a pivot pin 33 to enable the closure trigger 32 to be manipulated by a clinician. When the clinician grips the pistol grip portion 19 of the handle assembly 14, the closure trigger 32 can pivot from a starting or “unactuated” position to an “actuated” position and more particularly to a fully compressed or fully actuated position.

The handle assembly 14 and the frame 20 may operably support a firing drive system 80 configured to apply firing motions to corresponding portions of the interchangeable shaft assembly attached thereto. The firing drive system 80 may employ an electric motor 82 located in the pistol grip portion 19 of the handle assembly 14. The electric motor 82 may be a DC brushed motor having a maximum rotational speed of approximately 25,000 RPM, for example. In other arrangements, the motor may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. The electric motor 82 may be powered by a power source 90 that may comprise a removable power pack 92. The removable power pack 92 may comprise a proximal housing portion 94 configured to attach to a distal housing portion 96. The proximal housing portion 94 and the distal housing portion 96 are configured to operably support a plurality of batteries 98 therein. Batteries 98 may each comprise, for example, a Lithium Ion (LI) or other suitable battery. The distal housing portion 96 is configured for removable operable attachment to a control circuit board 100, which is operably coupled to the electric motor 82. Several batteries 98 connected in series may power the surgical instrument 10. The power source 90 may be replaceable and/or rechargeable.

The electric motor 82 can include a rotatable shaft (not shown) that operably interfaces with a gear reducer assembly 84 mounted in meshing engagement with a with a set, or rack, of drive teeth 122 on a longitudinally movable drive member 120. The longitudinally movable drive member 120 has a rack of drive teeth 122 formed thereon for meshing engagement with a corresponding drive gear 86 of the gear reducer assembly 84.

In use, a voltage polarity provided by the power source 90 can operate the electric motor 82 in a clockwise direction wherein the voltage polarity applied to the electric motor by the battery can be reversed in order to operate the electric motor 82 in a counter-clockwise direction. When the electric motor 82 is rotated in one direction, the longitudinally movable drive member 120 will be axially driven in the distal direction “DD.” When the electric motor 82 is driven in the opposite rotary direction, the longitudinally movable drive member 120 will be axially driven in a proximal direction “PD.” The handle assembly 14 can include a switch that can be configured to reverse the polarity applied to the electric motor 82 by the power source 90. The handle assembly 14 may include a sensor configured to detect the position of the longitudinally movable drive member 120 and/or the direction in which the longitudinally movable drive member 120 is being moved.

Actuation of the electric motor 82 can be controlled by a firing trigger 130 that is pivotally supported on the handle assembly 14. The firing trigger 130 may be pivoted between an unactuated position and an actuated position.

Turning back to FIG. 1 , the interchangeable shaft assembly 200 includes an end effector 300 comprising an elongated channel 302 configured to operably support a surgical staple cartridge 304 therein. The end effector 300 may include an anvil 306 that is pivotally supported relative to the elongated channel 302. The interchangeable shaft assembly 200 may include an articulation joint 270. Construction and operation of the end effector 300 and the articulation joint 270 are set forth in U.S. Patent Application Publication No. 2014/0263541, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, which is herein incorporated by reference in its entirety. The interchangeable shaft assembly 200 may include a proximal housing or nozzle 201 comprised of nozzle portions 202, 203. The interchangeable shaft assembly 200 may include a closure tube 260 extending along a shaft axis SA that can be utilized to close and/or open the anvil 306 of the end effector 300.

Turning back to FIG. 1 , the closure tube 260 is translated distally (direction “DD”) to close the anvil 306, for example, in response to the actuation of the closure trigger 32 in the manner described in the aforementioned reference U.S. Patent Application Publication No. 2014/0263541. The anvil 306 is opened by proximally translating the closure tube 260. In the anvil-open position, the closure tube 260 is moved to its proximal position.

FIG. 3 is an exploded view of one aspect of an end effector 300 of the surgical instrument 10 of FIG. 1 in accordance with one or more aspects of the present disclosure. The end effector 300 may include the anvil 306 and the surgical staple cartridge 304. In this non-limiting example, the anvil 306 is coupled to an elongated channel 302. For example, apertures 199 can be defined in the elongated channel 302 which can receive pins 152 extending from the anvil 306 and allow the anvil 306 to pivot from an open position to a closed position relative to the elongated channel 302 and surgical staple cartridge 304. A firing bar 172 is configured to longitudinally translate into the end effector 300. The firing bar 172 may be constructed from one solid section, or in various examples, may include a laminate material comprising, for example, a stack of steel plates. The firing bar 172 comprises an E-beam 178 and a cutting edge 182 at a distal end thereof. In various aspects, the E-beam may be referred to as an I-beam. A distally projecting end of the firing bar 172 can be attached to the E-beam 178 element in any suitable manner and can, among other things, assist in spacing the anvil 306 from a surgical staple cartridge 304 positioned in the elongated channel 302 when the anvil 306 is in a closed position. The E-beam 178 also can include a sharpened cutting edge 182 that can be used to sever tissue as the E-beam 178 is advanced distally by the firing bar 172. In operation, the E-beam 178 also can actuate, or fire, the surgical staple cartridge 304. The surgical staple cartridge 304 can include a molded cartridge body 194 that holds a plurality of staples 191 resting upon staple drivers 192 within respective upwardly open staple cavities 195. A wedge sled 190 is driven distally by the E-beam 178, sliding upon a cartridge tray 196 that holds together the various components of the surgical staple cartridge 304. The wedge sled 190 upwardly cams the staple drivers 192 to force out the staples 191 into deforming contact with the anvil 306 while the cutting edge 182 of the E-beam 178 severs clamped tissue.

The E-beam 178 can include upper pins 180 that engage the anvil 306 during firing. The E-beam 178 can further include middle pins 184 and a bottom foot 186 that can engage various portions of the cartridge body 194, cartridge tray 196, and elongated channel 302. When a surgical staple cartridge 304 is positioned within the elongated channel 302, a slot 193 defined in the cartridge body 194 can be aligned with a longitudinal slot 197 defined in the cartridge tray 196 and a slot 189 defined in the elongated channel 302. In use, the E-beam 178 can slide through the aligned longitudinal slots 193, 197, and 189 wherein, as indicated in FIG. 3 , the bottom foot 186 of the E-beam 178 can engage a groove running along the bottom surface of elongated channel 302 along the length of slot 189, the middle pins 184 can engage the top surfaces of cartridge tray 196 along the length of longitudinal slot 197, and the upper pins 180 can engage the anvil 306. In such circumstances, the E-beam 178 can space, or limit the relative movement between, the anvil 306 and the surgical staple cartridge 304 as the firing bar 172 is moved distally to fire the staples from the surgical staple cartridge 304 and/or incise the tissue captured between the anvil 306 and the surgical staple cartridge 304. Thereafter, the firing bar 172 and the E-beam 178 can be retracted proximally allowing the anvil 306 to be opened to release the two stapled and severed tissue portions.

Referring to FIG. 4 , in at least one arrangement, an interchangeable shaft assembly can be used in connection with an RF cartridge 1700 as well as a surgical staple/fastener cartridge.

The RF surgical cartridge 1700 includes a cartridge body 1710 that is sized and shaped to be removably received and supported in the elongate channel 1602. For example, the cartridge body 1710 may be configured to be removable retained in snap engagement with the elongate channel 1602. In at least one aspect, the cartridge body 1710 includes a centrally disposed elongate slot 1712 that extends longitudinally through the cartridge body to accommodate longitudinal travel of a knife therethrough.

The cartridge body 1710 is formed with a centrally disposed raised electrode pad 1720. The elongate slot 1712 extends through the center of the electrode pad 1720 and serves to divide the pad 1720 into a left pad segment 1720L and a right pad segment 1720R. A right flexible circuit assembly 1730R is attached to the right pad segment 1720R and a left flexible circuit assembly 1730L is attached to the left pad segment 1720L. In at least one arrangement for example, the right flexible circuit 1730R comprises a plurality of wires 1732R that may include, for example, wider wires/conductors for RF purposes and thinner wires for conventional stapling purposes that are supported or attached or embedded into a right insulator sheath/member 1734R that is attached to the right pad 1720R. In addition, the right flexible circuit assembly 1730R includes a “phase one”, proximal right electrode 1736R and a “phase two” distal right electrode 1738R. Likewise, the left flexible circuit assembly 1730L comprises a plurality of wires 1732L that may include, for example, wider wires/conductors for RF purposes and thinner wires for conventional stapling purposes that are supported or attached or embedded into a left insulator sheath/member 1734L that is attached to the left pad 1720L. In addition, the left flexible circuit assembly 1730L includes a “phase one”, proximal left electrode 1736L and a “phase two” distal left electrode 1738L. The left and right wires 1732L, 1732R are attached to a distal micro-chip 1740 mounted to the distal end portion of the cartridge body 1710.

The elongate channel 1602 includes a channel circuit 1670 that is supported in a recess 1621 that extends from the proximal end of the elongate channel 1602 to a distal location 1623 in the elongate channel bottom portion 1620. The channel circuit 1670 includes a proximal contact portion 1672 that contacts a distal contact portion 1169 of a flexible shaft circuit strip for electrical contact therewith. A distal end 1674 of the channel circuit 1670 is received within a corresponding wall recess 1625 formed in one of the channel walls 1622 and is folded over and attached to an upper edge 1627 of the channel wall 1622. A serial of corresponding exposed contacts 1676 are provided in the distal end 1674 of the channel circuit 1670. An end of a flexible cartridge circuit 1750 is attached to the distal micro-chip 1740 and is affixed to the distal end portion of the cartridge body 1710. Another end is folded over the edge of the cartridge deck surface 1711 and includes exposed contacts configured to make electrical contact with the exposed contacts 1676 of the channel circuit 1670. Thus, when the RF cartridge 1700 is installed in the elongate channel 1602, the electrodes as well as the distal micro-chip 1740 are powered and communicate with an onboard circuit board through contact between the flexible cartridge circuit 1750, the flexible channel circuit 1670, a flexible shaft circuit and slip ring assembly.

FIG. 5 is another exploded assembly view of portions of the interchangeable shaft assembly 200 according to one aspect of this disclosure. The interchangeable shaft assembly 200 includes a firing member 220 that is supported for axial travel within a shaft spine 210. The firing member 220 includes an intermediate firing shaft portion 222 that is configured for attachment to a distal portion or bar 280. The intermediate firing shaft portion 222 may include a longitudinal slot 223 in the distal end thereof which can be configured to receive a tab 284 on the proximal end 282 of the distal bar 280. The longitudinal slot 223 and the proximal end 282 can be sized and configured to permit relative movement therebetween and can comprise a slip joint 286. The slip joint 286 can permit the intermediate firing shaft portion 222 of the firing member 220 to be moved to articulate the end effector 300 without moving, or at least substantially moving, the bar 280. Once the end effector 300 has been suitably oriented, the intermediate firing shaft portion 222 can be advanced distally until a proximal sidewall of the longitudinal slot 223 comes into contact with the tab 284 in order to advance the distal bar 280. Advancement of the distal bar 280 causes the E-beam 178 to be advanced distally to fire the staple cartridge positioned within the channel 302.

Further to the above, the shaft assembly 200 includes a clutch assembly 400 which can be configured to selectively and releasably couple the articulation driver 230 to the firing member 220. In one form, the clutch assembly 400 includes a lock collar, or sleeve 402, positioned around the firing member 220 wherein the lock sleeve 402 can be rotated between an engaged position in which the lock sleeve 402 couples the articulation drive 230 to the firing member 220 and a disengaged position in which the articulation drive 230 is not operably coupled to the firing member 220. When lock sleeve 402 is in its engaged position, distal movement of the firing member 220 can move the articulation drive 230 distally and, correspondingly, proximal movement of the firing member 220 can move the articulation drive 230 proximally. When lock sleeve 402 is in its disengaged position, movement of the firing member 220 is not transmitted to the articulation drive 230 and, as a result, the firing member 220 can move independently of the articulation drive 230.

The lock sleeve 402 can comprise a cylindrical, or an at least substantially cylindrical, body including a longitudinal aperture 403 defined therein configured to receive the firing member 220. The lock sleeve 402 can comprise diametrically-opposed, inwardly-facing lock protrusions 404 and an outwardly-facing lock member 406. The lock protrusions 404 can be configured to be selectively engaged with the firing member 220. More particularly, when the lock sleeve 402 is in its engaged position, the lock protrusions 404 are positioned within a drive notch 224 defined in the firing member 220 such that a distal pushing force and/or a proximal pulling force can be transmitted from the firing member 220 to the lock sleeve 402. When the lock sleeve 402 is in its engaged position, the second lock member 406 is received within a drive notch 232 defined in the articulation driver 230 such that the distal pushing force and/or the proximal pulling force applied to the lock sleeve 402 can be transmitted to the articulation driver 230. In effect, the firing member 220, the lock sleeve 402, and the articulation driver 230 will move together when the lock sleeve 402 is in its engaged position. On the other hand, when the lock sleeve 402 is in its disengaged position, the lock protrusions 404 may not be positioned within the drive notch 224 of the firing member 220 and, as a result, a distal pushing force and/or a proximal pulling force may not be transmitted from the firing member 220 to the lock sleeve 402. Correspondingly, the distal pushing force and/or the proximal pulling force may not be transmitted to the articulation driver 230. In such circumstances, the firing member 220 can be slid proximally and/or distally relative to the lock sleeve 402 and the proximal articulation driver 230.

The shaft assembly 200 further includes a switch drum 500 that is rotatably received on the closure tube 260. The switch drum 500 comprises a hollow shaft segment 502 that has a shaft boss 504 formed thereon for receive an outwardly protruding actuation pin 410 therein. In various circumstances, the actuation pin 410 extends through a slot 267 into a longitudinal slot 408 provided in the lock sleeve 402 to facilitate axial movement of the lock sleeve 402 when it is engaged with the articulation driver 230. A rotary torsion spring 420 is configured to engage the boss 504 on the switch drum 500 and a portion of the nozzle housing 203 as shown in FIG. 5 to apply a biasing force to the switch drum 500. The switch drum 500 can further comprise at least partially circumferential openings 506 defined therein which, referring to FIGS. 5 and 6 , can be configured to receive circumferential mounts extending from the nozzle halves 202, 203 and permit relative rotation, but not translation, between the switch drum 500 and the proximal nozzle 201. The mounts also extend through openings 266 in the closure tube 260 to be seated in recesses 211 in the shaft spine 210. However, rotation of the nozzle 201 to a point where the mounts reach the end of their respective openings 506 in the switch drum 500 will result in rotation of the switch drum 500 about the shaft axis SA-SA. Rotation of the switch drum 500 will ultimately result in the rotation of the actuation pin 410 and the lock sleeve 402 between its engaged and disengaged positions. Thus, in essence, the nozzle 201 may be employed to operably engage and disengage the articulation drive system with the firing drive system in the various manners described in further detail in U.S. patent application Ser. No. 13/803,086.

The shaft assembly 200 can comprise a slip ring assembly 600 which can be configured to conduct electrical power to and/or from the end effector 300 and/or communicate signals to and/or from the end effector 300, for example. The slip ring assembly 600 can comprise a proximal connector flange 604 mounted to a chassis flange 242 extending from the chassis 240 and a distal connector flange 601 positioned within a slot defined in the nozzle halves 202, 203. The proximal connector flange 604 can comprise a first face and the distal connector flange 601 can comprise a second face which is positioned adjacent to and movable relative to the first face. The distal connector flange 601 can rotate relative to the proximal connector flange 604 about the shaft axis SA-SA. The proximal connector flange 604 can comprise a plurality of concentric, or at least substantially concentric, conductors 602 defined in the first face thereof. A connector 607 can be mounted on the proximal side of the connector flange 601 and may have a plurality of contacts, wherein each contact corresponds to and is in electrical contact with one of the conductors 602. Such an arrangement permits relative rotation between the proximal connector flange 604 and the distal connector flange 601 while maintaining electrical contact therebetween. The proximal connector flange 604 can include an electrical connector 606 which can place the conductors 602 in signal communication with a circuit board mounted to the shaft chassis 240, for example. In at least one instance, a wiring harness comprising a plurality of conductors can extend between the electrical connector 606 and the circuit board. U.S. patent application Ser. No. 13/800,067, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, is incorporated by reference in its entirety. U.S. patent application Ser. No. 13/800,025, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, is incorporated by reference in its entirety. Further details regarding slip ring assembly 600 may be found in U.S. patent application Ser. No. 13/803,086.

The shaft assembly 200 can include a proximal portion which is fixably mounted to the handle assembly 14 and a distal portion which is rotatable about a longitudinal axis. The rotatable distal shaft portion can be rotated relative to the proximal portion about the slip ring assembly 600. The distal connector flange 601 of the slip ring assembly 600 can be positioned within the rotatable distal shaft portion. Moreover, further to the above, the switch drum 500 can also be positioned within the rotatable distal shaft portion. When the rotatable distal shaft portion is rotated, the distal connector flange 601 and the switch drum 500 can be rotated synchronously with one another. In addition, the switch drum 500 can be rotated between a first position and a second position relative to the distal connector flange 601. When the switch drum 500 is in its first position, the articulation drive system may be operably disengaged from the firing drive system and, thus, the operation of the firing drive system may not articulate the end effector 300 of the shaft assembly 200. When the switch drum 500 is in its second position, the articulation drive system may be operably engaged with the firing drive system and, thus, the operation of the firing drive system may articulate the end effector 300 of the shaft assembly 200. When the switch drum 500 is moved between its first position and its second position, the switch drum 500 is moved relative to distal connector flange 601.

In various examples, the shaft assembly 200 can comprise at least one sensor configured to detect the position of the switch drum 500. The distal connector flange 601 can comprise a Hall effect sensor 605, for example, and the switch drum 500 can comprise a magnetic element, such as permanent magnet 505, for example. The Hall effect sensor 605 can be configured to detect the position of the permanent magnet 505. When the switch drum 500 is rotated between its first position and its second position, the permanent magnet 505 can move relative to the Hall effect sensor 605. In various examples, Hall effect sensor 605 can detect changes in a magnetic field created when the permanent magnet 505 is moved. The Hall effect sensor 605 can be in signal communication with a control circuit, for example. Based on the signal from the Hall effect sensor 605, a microcontroller on the control circuit can determine whether the articulation drive system is engaged with or disengaged from the firing drive system.

A surgical instrument may not be able to use a rotatable shaft assembly effectively by using general wires to communicate power and signals between a fixed shaft portion and a rotatable shaft portion of the shaft assembly because the wires may get twisted or even damaged due to the repeated rotation of the shaft assembly. One way to overcome this deficiency may be to use a ring assembly instead of wires to communicate power and signals to the rotatable shaft portion. For example, a first flange with electrodes may be attached to the fixed shaft portion and a second flange with electrodes may rotate relative to the electrodes of the first flange. A gap is necessarily formed between the first flange and the second flange to permit the rotation of the second flange relative to the first flange. In order to maintain an electrical connection during the rotation of the rotatable shaft portion, the electrodes of the first and second flanges may be exposed at an interface therebetween. The gap may permit water and/or other body fluids ingress into the area between the first and second flanges where the electrode interface resides. Accordingly, the electrode interface may become exposed to water and other body fluids during surgery. Upon touching the exposed electrodes, the water and/or body fluids may cause signal noise or even loss of power/signals.

Aspects of the present disclosure improve slip ring assemblies in surgical instruments that that are exposed to water and/or body fluids during their operation. Aspects of the present disclosure may prevent signal noise and loss of power and signals by providing an insulative barrier to prevent water or fluids from reaching the electrodes.

Referring to FIG. 10-14 , a slip ring assembly 1400 is illustrated. The slip ring assembly 1400 is similar in many respects to the slip ring assembly 600. For example, the slip ring assembly 1400 can be configured to conduct electrical power to and/or from the surgical end effector 300 and/or communicate signals to and/or from the surgical end effector 300, back to a circuit board, while facilitating rotational travel of a distal shaft portion of a shaft assembly relative to a proximal shaft portion of the shaft assembly. A shaft assembly 200 can be equipped with the slip ring assembly 1400 in lieu of the slip ring assembly 600, for example. In various examples a Zero Insertion Force (ZIF) connector can be coupled to the slip ring assembly 1400 to transmit electrical signals and/or power to the end effector 300.

The slip ring assembly 1400 can be incorporated into the shaft assembly 200. For example, a proximal connector 1401 of the slip ring assembly 1400 can be fixed or attached to a proximal shaft portion of the shaft assembly 200. In one arrangement, the proximal connector 1401 can be mounted to the chassis flange 242 (FIG. 8 ) in the proximal shaft portion of the shaft assembly 200.

A distal connector 1402 of the slip ring assembly 1400 can be fixed or attached to a distal shaft portion of the shaft assembly 200. In a user-controlled rotation of the shaft assembly 200, the distal shaft portion is rotated relative to the proximal shaft portion. The rotation of the distal shaft assembly causes the distal connector 1402 to be rotated relative to the proximal connector 1401. In an assembled configuration, the slip ring assembly 1400 comprises a doughnut shape or a cylindrical shape that includes a central opening 1419 configured to receive the closure tube 260.

The proximal connector 1401, as illustrated in FIG. 10 , can be in the form of a slip ring that includes concentric and/or radially disposed conductors 1403 that are spaced apart from one another. The conductors 1403 comprise annular or disk-shaped profiles that are concentric about a longitudinal axis extending through the opening 1419. The conductors 1403 in FIG. 10 have continuous or uninterrupted profiles. In other examples, one or more of the conductors 1403 may have an interrupted profile. In various examples, as illustrated in FIG. 10 , the conductors 1403 are mounted on the proximal connector 1401

When the slip ring assembly 1400 is assembled, conductors 1404 of the distal connector 1402 are configured to be in contact with opposing conductors 1403 of the proximal connector 1401. In certain arrangements, the contact is maintained, or at least substantially maintained, while the distal connector 1402 and the conductors 1404 are rotated relative to the proximal connector 1401 and the conductors 1403.

In various examples, the conductors 1404 can be in the form of resiliently biased pins, resiliently biased leaf springs, resiliently biased lever arms with end contacts, and/or any other spring contacts as will be apparent to one of ordinary skill in the art in view of the teachings herein. A conductor 1404 may include a silver graphite tip on the end of a beryllium copper leaf spring or a metallic gold alloy wire, for example. In various examples, the conductors 1404 are in the form of resiliently biased leaf springs.

The conductors 1404 are spaced apart. Increasing the distance between adjacent conductors 1404 reduces the likelihood of a body of water connecting them. The conductors 1404 can be grouped in two groups on opposite halves of the distal connector 1402. In some examples, as illustrated in FIG. 11 , a group of conductors 1404 are radially and laterally spaced apart from one another to increase the distance between adjacent conductors 1404. Said another way, a group of conductors 1404 can be arranged on a distal connector 1402 in an arcuate pattern. In some examples, the conductors 1404 that are spaced apart radially can be disposed at an angle α defined with respect to a common point at the center of the distal connector 1402.

In certain arrangements, the angle α can be selected from a range of about 30° to about 90°, for example. In other instances, the angle α can be selected from a range of about 40° to about 70°, for example. In other instances, the angle α can be selected from a range of about 30° to about 90°, for example. In one example, the angle α can be about 50°. Other values for the angle between adjacent conductors 1404 are contemplated by the present disclosure. In various arrangements, different adjacent conductors 1404 can be spaced apart radially at different angles or the same angle.

Referring to FIG. 11 , adjacent conductors 1404 in a row can be spaced apart by a distance (d1) defined between two ends of the adjacent conductors 1404. In some examples, the distance (d1) can be selected from a range of about 0.025″ to about 0.200″. In some examples, the distance (d1) can be selected from a range of about 0.050″ to about 0.150″. In some examples, the distance (d1) can be about 0.075″. In some examples, the distance (d1) can be about 0.100″.

Further to the above, the slip ring assembly 1400 further includes a flexible member 1410 disposed between the proximal connector 1401 and the distal connector 1402. The flexible member 1410 defines an interface between the proximal connector 1401 and the distal connector 1402 in the form of a gasket or a seal configured to resist water flow between the proximal connector 1401 and distal connector 1402. In some examples, the flexible member 1410 is configured to resist water flow toward the conductors 1403 and/or the conductors 1404.

Referring to FIG. 14 , the flexible member 1410 includes a body portion 1411 and flexible portions 1412 protruding from the body portion 1411. The body portion 1411 and/or flexible portions 1412 can be elastically deformed, flattened, and/or spread against the proximal connector 1401 to resist water flow toward and/or trap water away from the conductors 1403 and/or the conductors 1404.

Referring to FIG. 12 , the flexible member 1410 is assembled with the distal connector 1402. In some example, the flexible member 1410 includes cutouts or openings 1414 configured to receive the conductors 1404. In an assembled configuration of the slip ring assembly 1400, as illustrated in FIG. 14 , the conductors 1403 of the proximal connector 1401 are inserted through the openings 1414 of flexible member 1410 and are brought into contact with the conductors 1404 of the distal connector 1402. In some examples, the flexible member 1410 is compressed, or at least partially compressed, between the proximal connector 1401 and the distal connector 1402 which causes the flexible portions 1412 to be elastically deformed, flattened, and/or spread against the proximal connector 1401.

A flexible portion 1412 can have a length that is substantially greater than a width of the flexible portion 1412. In some examples, a flexible portion 1412 can have a height that is substantially less than a length of the flexible portion 1412. In other examples, however, the length, width and height of each flexible portion 1412 may vary.

In some examples, the flexible portions 1412 may form tread elements that define a treaded surface that is configured to trap water away from the conductors 1403 and/or the conductors 1404. In some examples, the tread pattern can be arranged in a tread pattern.

The spacing between adjacent flexible portions 1412 may vary. In some examples, the spacing between adjacent flexible portions 1412 can be substantially constant throughout a tread pattern comprising a number of flexible portions 1412 extending from the body portion 1411. In other examples, the spacing between adjacent flexible portions 1412 may vary throughout a tread pattern. In one example, the spacing between adjacent flexible portions 1412 may be substantially similar throughout a tread pattern.

In various examples, the cross-sectional shape of one or more flexible portion 1412 may vary. In some examples, each flexible portion 1412 can be associated with a substantially triangular cross-sectional shape. In other examples, however, each flexible portion 1412 can have other types of cross-sectional shapes, including, but not limited to: rounded, rectangular, polygonal, regular and irregular cross-sectional shapes, as well as any other types of cross-sectional shapes. Certain tread patterns defined by flexible portions 1412 can be arranged in substantially nonlinear configurations.

Referring to FIG. 12 , in various examples, the flexible portions 1412 are arranged in a series of concentric and radially disposed ribs 1412 a-1412 h that are separated by circular grooves or channels 1415. The ribs may form a corrugated outer surface of the body portion 1411 that can be positioned against the proximal connector 1401, as illustrated in FIG. 14 . The ribs can be similarly shaped or comprise different shapes. The ribs can be closed concentric geometric figures such as, for example, an outermost rib 1412 a and an innermost rib 1412 h. Alternatively, certain ribs may have profiles that are interrupted by cutouts or openings 1414 that are configured to receive the conductors 1403.

In some examples, the outermost rib 1412 a and innermost rib 1412 h form inner and outer watertight barriers that prevent, or at least resist, ingress of water and/or other body fluids into the space between the proximal connector 1401 and the distal connector 1402. Furthermore, the grooves or channels 1415 are configured to trap water that manages to pass through the outermost rib 1412 a and/or the innermost rib 1412 h to retain such water away from the conductors 1403 and/or the conductors 1404.

Referring to FIG. 13 , a distal connector 1402′ is assembled with a flexible member 1410′. The distal connector 1402′ and the flexible member 1410′ are similar in many respects to the distal connector 1402 and the flexible member 1410, respectively. For example, the distal connector 1402′ includes conductors 1404′ that are similar in many respects to the conductors 1404. The conductors 1404′, however, are arranged onto the distal connector 1402′ in a different arrangement than the arrangement of the conductors 1404 onto the distal connector 1402. For example, a distal connector 1402′ includes a group of conductors 1404′ that are laterally spaced apart but are radially aligned with one another. The conductors 1404′ can be grouped in two groups on opposite halves of the distal connector 1402′. As illustrated in FIG. 13 , a group of the conductors 1404′ can be arranged in a row 1418. Adjacent conductors 1404′ in a row can be laterally spaced apart by a distance (d2). In some examples, the distance (d2) can be selected from a range of about 0.005″ to about 0.075″. In some examples, the distance (d2) can be selected from a range of about 0.015″ to about 0.055″. In some examples, the distance (d2) can be about 0.015″. In some examples, the distance (d2) can be about 0.050″.

The flexible member 1410′ is also similar in many respects to the flexible member 1410. For example, the flexible member 1410′ includes ribs 1412′a-1412′h that are similar in many respects to the ribs 1412 a-1412 h of the flexible member 1410. The flexible member 1410′, however, includes a different cutout arrangement configured to accommodate the conductors 1404′.

In various examples, the flexible members 1410, 1410′ are made, or at least partially made, from an elastomeric material. In at least one example, the flexible members 1410, 1410′ are made, or at least partially made, from Polyurethane or silicone. The flexible members 1410, 1410′ can be manufactured using any suitable manufacturing technique such as, for example, casting or injection molding.

Although various devices have been described herein in connection with certain embodiments, modifications and variations to those embodiments may be implemented. Particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined in whole or in part, with the features, structures or characteristics of one ore more other embodiments without limitation. Also, where materials are disclosed for certain components, other materials may be used. Furthermore, according to various embodiments, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to perform a given function or functions. The foregoing description and following claims are intended to cover all such modification and variations.

The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, a device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps including, but not limited to, the disassembly of the device, followed by cleaning or replacement of particular pieces of the device, and subsequent reassembly of the device. In particular, a reconditioning facility and/or surgical team can disassemble a device and, after cleaning and/or replacing particular parts of the device, the device can be reassembled for subsequent use. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.

The devices disclosed herein may be processed before surgery. First, a new or used instrument may be obtained and, when necessary, cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, and/or high-energy electrons. The radiation may kill bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a medical facility. A device may also be sterilized using any other technique known in the art, including but not limited to beta radiation, gamma radiation, ethylene oxide, plasma peroxide, and/or steam.

While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles.

Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials do not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

Various aspects of the subject matter described herein are set out in the following examples:

EXAMPLE 1

A slip ring assembly for use with a surgical shaft. The slip ring assembly comprises a first connector and a first conductor mounted on the first connector. The slip ring assembly further comprises a second connector rotatable relative to the first connector, a second conductor mounted on the second connector, wherein the second conductor is in contact with the first conductor, and an interface between the first connector and the second connector, wherein the interface is configured to trap water away from at least one of the first conductor and the second conductor.

EXAMPLE 2

The slip ring assembly of Example 1, wherein the interface comprises a body portion that includes an opening to receive the second conductor.

EXAMPLE 3

The slip ring assembly of one or more of Example 1 through Example 2, wherein the interface comprises ribs protruding from the body portion.

EXAMPLE 4

The slip ring assembly of Example 3, wherein the ribs are concentric.

EXAMPLE 5

The slip ring assembly of one or more of Example 1 through Example 4, wherein the interface is flexible.

EXAMPLE 6

The slip ring assembly of one or more of Example 1 through Example 5, wherein the interface is comprised of an elastomeric material.

EXAMPLE 7

The slip ring assembly of one or more of Example 1 through Example 6, wherein the interface is fixed to the second connector.

EXAMPLE 8

The slip ring assembly of one or more of Example 1 through Example 7, wherein the interface is rotatable with the second connector relative to the first connector.

EXAMPLE 9

A surgical shaft assembly comprising a proximal shaft portion and a distal shaft portion rotatable relative to the proximal shaft portion. The proximal shaft portion comprises a proximal connector supported in the proximal shaft portion and first conductors mounted on the proximal connector. The distal shaft portion comprises a distal connector supported in the distal shaft portion, second conductors mounted on the distal connector, wherein the second conductors are spaced apart laterally and radially from one another, and a gasket disposed between the proximal connector and the distal connector, wherein the gasket is configured to resist water flow toward at least one of the first conductors and the second conductors.

EXAMPLE 10

The surgical shaft assembly of Example 9, wherein the gasket comprises openings configured to receive the second conductors.

EXAMPLE 11

The surgical shaft assembly of one or more of Example 9 through Example 10, wherein the gasket comprises tread elements protruding therefrom.

EXAMPLE 12

The surgical shaft assembly of Example 11, wherein the tread elements are concentric.

EXAMPLE 13

The surgical shaft assembly of one or more of Example 9 through Example 12, wherein the gasket is flexible.

EXAMPLE 14

The surgical shaft assembly of one or more of Example 9 through Example 13, wherein the gasket is comprised of an elastomeric material.

EXAMPLE 15

The surgical shaft assembly of one or more of Example 9 through Example 14, wherein the gasket is fixed to the distal connector.

EXAMPLE 16

The surgical shaft assembly of one or more of Example 9 through Example 15, wherein the gasket is rotatable with the distal connector relative to the proximal connector.

EXAMPLE 17

A slip ring assembly for use with a surgical shaft assembly. The slip ring assembly comprises a slip ring, a first conductor mounted on the slip ring and a commutator rotatable relative to the slip ring. The slip ring assembly further comprises a second conductor mounted to the commutator and a flexible member disposed between the slip ring and the commutator. The flexible member comprises a body portion and flexible portions extending from the body portions, wherein the flexible portions are elastically deformed against the slip ring.

EXAMPLE 18

The slip ring assembly of Example 17, wherein the body portions comprises an opening configured to receive the second conductor.

EXAMPLE 19

The slip ring assembly of one or more of Example 17 through Example 18, wherein the flexible member is fixed to the commutator.

EXAMPLE 20

The slip ring assembly of one or more of Example 17 through Example 19, wherein the flexible member is rotatable with the commutator relative to the slip ring. 

The invention claimed is:
 1. A slip ring assembly for use with a surgical shaft assembly, the slip ring assembly comprising: a first connector comprising a body portion, wherein the body portion comprises an outer surface, and wherein the first connector defines a first aperture therethrough; a first conductor comprising a conductive element directly mounted on the first connector, wherein the first conductor extends beyond the outer surface of the first connector; a second connector rotatable relative to the first connector, wherein the second connector defines a second aperture therethrough; a second conductor mounted on the second connector; and an interface between the first connector and the second connector, wherein the interface is configured to prevent the first connector from engaging the second connector, wherein the outer surface of the first connector is positioned adjacent to the interface, wherein the interface defines a third aperture therethrough, wherein the first aperture, the second aperture, and the third aperture cooperatively define a central passage through the slip ring assembly, wherein the central passage is spaced apart from the first conductor and the second conductor, and wherein the interface includes: a body portion; an opening defined in the body portion, wherein the first conductor and the second conductor are configured to extend through and electrically engage one another in the opening; and a plurality of ribs comprising: an outermost rib of the plurality of ribs that defines an outer edge of the interface; an innermost rib of the plurality of ribs that defines the third aperture through the interface; the outermost rib and another of the plurality of ribs defining a conductorless outer groove, wherein the outer groove is configured to retain fluid away from at least one of the first conductor and the second conductor; and the innermost rib and another of the plurality of ribs defining a conductorless inner groove, wherein the inner groove is configured to retain fluid away from at least one of the first conductor and the second conductor.
 2. The slip ring assembly of claim 1, wherein the plurality of ribs protrude from the body portion.
 3. The slip ring assembly of claim 1, wherein the plurality of ribs are concentric.
 4. The slip ring assembly of claim 1, wherein the interface is flexible.
 5. The slip ring assembly of claim 1, wherein the interface is comprised of an elastomeric material.
 6. The slip ring assembly of claim 1, wherein the interface is fixed to the second connector.
 7. The slip ring assembly of claim 6, wherein the interface is rotatable with the second connector relative to the first connector.
 8. The slip ring assembly of claim 1, wherein the plurality of ribs extend from the interface toward the outer surface of the first connector.
 9. The slip ring assembly of claim 1, wherein the first conductor is mounted on the outer surface of the first connector.
 10. The slip ring assembly of claim 1, wherein the first conductor extends around the central passage.
 11. A surgical shaft assembly, comprising: a proximal shaft portion, comprising: a proximal connector supported in the proximal shaft portion, wherein the proximal connector comprises an outer surface, and wherein the proximal connector defines a first aperture therethrough; and first conductors, wherein each of the first conductors comprises an electrically conductive element directly mounted on the proximal connector, wherein the first conductors extend beyond the outer surface of the proximal connector; and a distal shaft portion rotatable relative to the proximal shaft portion, wherein the distal shaft portion comprises: a distal connector supported in the distal shaft portion, wherein the distal connector defines a second aperture therethrough; second conductors mounted on the distal connector, wherein the second conductors are spaced apart laterally and radially from one another; and a gasket disposed between the proximal connector and the distal connector, wherein the gasket is configured to prevent the proximal connector from engaging the distal connector, wherein the gasket is positioned adjacent to the outer surface of the proximal connector when the surgical shaft assembly is in an assembled configuration, wherein the gasket defines a third aperture therethrough, wherein the first aperture, the second aperture, and the third aperture cooperatively define a central passage that is spaced apart from the first conductors and the second conductors, and wherein the gasket includes a plurality of tread elements comprising: an outermost tread element of the plurality of tread elements that defines an outer edge of the gasket; an innermost tread element of the plurality of tread elements that defines the third aperture through the gasket; the outermost tread element and another of the plurality of tread elements defining a conductorless outer groove, wherein the outer groove is configured to prevent fluid from contacting at least one of the first conductors; and the innermost tread element and another of the plurality of tread elements defining a conductorless inner groove, wherein the inner groove is configured to prevent fluid from contacting at least one of the first conductors.
 12. The surgical shaft assembly of claim 11, wherein the gasket comprises openings configured to receive the second conductors.
 13. The surgical shaft assembly of claim 12, wherein the gasket comprises a body portion from which the tread elements protrude.
 14. The surgical shaft assembly of claim 11, wherein the plurality of tread elements are concentric.
 15. The surgical shaft assembly of claim 11, wherein the gasket is flexible.
 16. The surgical shaft assembly of claim 11, wherein the gasket is comprised of an elastomeric material.
 17. The surgical shaft assembly of claim 11, wherein the gasket is fixed to the distal connector.
 18. The surgical shaft assembly of claim 17, wherein the gasket is rotatable with the distal connector relative to the proximal connector.
 19. A slip ring assembly for use with a surgical shaft assembly, the slip ring assembly comprising: a slip ring comprising an outer surface, wherein the slip ring defines a first aperture therethrough; a first conductor comprising an electrically conductive element directly mounted on the slip ring, wherein the first conductor extends beyond the outer surface of the slip ring; a commutator rotatable relative to the slip ring, wherein the commutator defines a second aperture therethrough; a second conductor mounted on the commutator; and a flexible member disposed between the slip ring and the commutator, wherein the flexible member is configured to be positioned adjacent to the outer surface of the slip ring, wherein the flexible member defines a third aperture therethrough, wherein the first aperture, the second aperture, and the third aperture cooperatively define a central passage through the slip ring assembly, wherein the central passage is spaced apart from the first conductor and the second conductor, and wherein the flexible member comprises: a body portion; an opening defined in the body portion, wherein the first conductor and the second conductor are configured to extend through and contact one another in the opening; and flexible portions extending from the body portion, wherein the flexible portions are elastically deformed against the slip ring, and wherein the flexible portions comprise; an outermost flexible portion of the flexible portions that defines an outer edge of the flexible member; an innermost flexible portion of the flexible portions that defines the third aperture through the flexible member; the outermost flexible portion and another of the flexible portions defining a conductorless outer groove; and the innermost flexible portion and another of the flexible portions defining a conductorless inner groove.
 20. The slip ring assembly of claim 19, wherein the flexible member is fixed to the commutator.
 21. The slip ring assembly of claim 20, wherein the flexible member is rotatable with the commutator relative to the slip ring. 